LocationHelper.java

import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.content.IntentSender;
import android.content.pm.PackageManager;
import android.location.Location;
import android.location.LocationManager;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.v4.app.ActivityCompat;
import android.util.Log;
import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.api.GoogleApiClient;
import com.google.android.gms.common.api.PendingResult;
import com.google.android.gms.common.api.ResultCallback;
import com.google.android.gms.common.api.Status;
import com.google.android.gms.location.*;

public class LocationHelper implements GoogleApiClient.OnConnectionFailedListener, ResultCallback<Status> {

    private static final String TAG = LocationHelper.class.getSimpleName();
    private static final int REQUEST_CODE_LOCATION_SETTING = 9876;

    private Context context;
    private GoogleApiClient googleApiClient;
    private Location lastKnownLocation;
    private LocationUpdateListener locationUpdateListener;

    // location request parameter
    private long interval = 0;                  // time in millisecond
    private long fastestInterval = 0;           // time in millisecond
    private float smallestDisplacement = 0;     // meter
    private int priority = LocationRequest.PRIORITY_HIGH_ACCURACY;
    private boolean isContinuousRequest = false;


    private LocationListener locationListener = new LocationListener() {
        @Override
        public void onLocationChanged(Location location) {
            Log.e(TAG, "onLocationChanged: " + location.toString());
            //Preferences.getInstance().saveLastLocation(location);
            if (locationUpdateListener != null) {
                locationUpdateListener.onLocationUpdate(location);
            }
        }
    };

    private GoogleApiClient.ConnectionCallbacks continuousRequest = new GoogleApiClient.ConnectionCallbacks() {
        @Override
        public void onConnected(Bundle bundle) {
            if (isLocationEnabled(context)) {
                startLocationUpdates();
            } else {
                enableLocationRequest();
            }
        }

        @Override
        public void onConnectionSuspended(int cause) {
        }
    };

    private GoogleApiClient.ConnectionCallbacks singleRequest = new GoogleApiClient.ConnectionCallbacks() {
        @Override
        public void onConnected(Bundle bundle) {
            if (isLocationEnabled(context)) {
                getLastKnownLocation();
            } else {
                enableLocationRequest();
            }
        }

        @Override
        public void onConnectionSuspended(int cause) {
        }
    };

    public LocationHelper(Context context) {
        this.context = context;
    }

    public static boolean isLocationEnabled(Context context) {
        LocationManager locationManager = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);
        return locationManager != null && locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);
    }

    /*public boolean isLocationEnabled(Context context) {
        int locationMode = 0;
        String locationProviders;

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
            try {
                locationMode = Settings.Secure.getInt(context.getContentResolver(), Settings.Secure.LOCATION_MODE);

            } catch (Settings.SettingNotFoundException e) {
                e.printStackTrace();
                return false;
            }
            return locationMode != Settings.Secure.LOCATION_MODE_OFF;
        } else {
            locationProviders = Settings.Secure.getString(context.getContentResolver(), Settings.Secure.LOCATION_PROVIDERS_ALLOWED);
            return !TextUtils.isEmpty(locationProviders);
        }
    }*/

    @Override
    public void onConnectionFailed(@NonNull ConnectionResult connectionResult) {
    }

    private void setupGoogleApiClient(GoogleApiClient.ConnectionCallbacks connectionCallbacks) {
        googleApiClient = new GoogleApiClient.Builder(context)
                .addApi(LocationServices.API)
                .addConnectionCallbacks(connectionCallbacks)
                .addOnConnectionFailedListener(this)
                .build();
        googleApiClient.connect();
    }

    public LocationHelper setInterval(long interval) {
        this.interval = interval;
        return this;
    }

    public LocationHelper setFastestInterval(long fastestInterval) {
        this.fastestInterval = fastestInterval;
        return this;
    }

    public LocationHelper setSmallestDisplacement(float smallestDisplacement) {
        this.smallestDisplacement = smallestDisplacement;
        return this;
    }

    public LocationHelper setPriority(int priority) {
        this.priority = priority;
        return this;
    }

    public LocationHelper setLocationUpdateListener(LocationUpdateListener locationUpdateListener) {
        this.locationUpdateListener = locationUpdateListener;
        return this;
    }

    public void stop() {
        if (googleApiClient != null && googleApiClient.isConnected()) {
            stopLocationUpdates();
        }
    }

    /**
     * create location request
     *
     * @return instance of LocationRequest
     */
    private LocationRequest createLocationRequest() {
        LocationRequest mLocationRequest = new LocationRequest();
        mLocationRequest.setInterval(interval);
        mLocationRequest.setFastestInterval(fastestInterval);
        mLocationRequest.setSmallestDisplacement(smallestDisplacement);
        mLocationRequest.setPriority(priority);
        return mLocationRequest;
    }

    public void requestSingleLocation() {
        isContinuousRequest = false;
        // set google api client
        setupGoogleApiClient(singleRequest);
    }

    private void getLastKnownLocation() {
        if (ActivityCompat.checkSelfPermission(context, android.Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(context, android.Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            return;
        }
        if (googleApiClient == null || !googleApiClient.isConnected()) {
            setupGoogleApiClient(singleRequest);
            return;
        }

        lastKnownLocation = LocationServices.FusedLocationApi.getLastLocation(googleApiClient);
        if (lastKnownLocation != null) {
            if (locationUpdateListener != null) {
                locationUpdateListener.onLocationUpdate(lastKnownLocation);
            }
            if (googleApiClient != null) {
                googleApiClient.disconnect();
            }
        } else {
            LocationServices.FusedLocationApi.requestLocationUpdates(googleApiClient, createLocationRequest(), new LocationListener() {
                @Override
                public void onLocationChanged(Location location) {
                    if (locationUpdateListener != null) {
                        locationUpdateListener.onLocationUpdate(location);
                    }
                    if (googleApiClient != null && googleApiClient.isConnected()) {
                        PendingResult<Status> pendingResult = LocationServices.FusedLocationApi.removeLocationUpdates(googleApiClient, locationListener);
                        pendingResult.setResultCallback(new ResultCallback<Status>() {
                            @Override
                            public void onResult(@NonNull Status status) {
                                Log.e(TAG, "onResult Single (Stop): " + status);
                                if (status == Status.RESULT_SUCCESS) {
                                    if (googleApiClient != null && googleApiClient.isConnected()) {
                                        googleApiClient.disconnect();
                                    }
                                }
                            }
                        });
                    }
                }
            });
        }
    }

    public void requestContinuousLocation() {
        isContinuousRequest = true;
        // set google api client
        setupGoogleApiClient(continuousRequest);
    }

    private void startLocationUpdates() {
        if (ActivityCompat.checkSelfPermission(context, android.Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(context, android.Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            return;
        }
        if (googleApiClient != null && googleApiClient.isConnected()) {
            PendingResult<Status> pendingResult = LocationServices.FusedLocationApi.requestLocationUpdates(googleApiClient, createLocationRequest(), locationListener);
            pendingResult.setResultCallback(this);
        }
    }

    private void stopLocationUpdates() {
        if (ActivityCompat.checkSelfPermission(context, android.Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(context, android.Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            return;
        }
        PendingResult<Status> pendingResult = LocationServices.FusedLocationApi.removeLocationUpdates(googleApiClient, locationListener);
        pendingResult.setResultCallback(new ResultCallback<Status>() {
            @Override
            public void onResult(@NonNull Status status) {
                Log.e(TAG, "onResult (Stop): " + status);
                if (status == Status.RESULT_SUCCESS) {
                    if (googleApiClient != null && googleApiClient.isConnected()) {
                        googleApiClient.disconnect();
                    }
                }
            }
        });
    }

    @Override
    public void onResult(@NonNull Status status) {
        Log.e(TAG, "onResult: " + status);
    }

    public void enableLocationRequest() {
        if (googleApiClient == null) {
            return;
        }
        LocationSettingsRequest.Builder builder = new LocationSettingsRequest.Builder()
                .addLocationRequest(createLocationRequest());
        builder.setAlwaysShow(true); //this is the key ingredient

        PendingResult<LocationSettingsResult> result =
                LocationServices.SettingsApi.checkLocationSettings(googleApiClient, builder.build());

        result.setResultCallback(new ResultCallback<LocationSettingsResult>() {
            @Override
            public void onResult(LocationSettingsResult result) {
                final Status status = result.getStatus();
                final LocationSettingsStates state = result.getLocationSettingsStates();
                switch (status.getStatusCode()) {
                    case LocationSettingsStatusCodes.SUCCESS:
                        // All location settings are satisfied. The client can initialize location
                        // requests here.
                        break;
                    case LocationSettingsStatusCodes.RESOLUTION_REQUIRED:
                        // Location settings are not satisfied. But could be fixed by showing the user
                        // a dialog.
                        try {
                            // Show the dialog by calling startResolutionForResult(),
                            // and check the result in onActivityResult().
                            if (context instanceof Activity) {
                                status.startResolutionForResult((Activity) context, REQUEST_CODE_LOCATION_SETTING);
                            }
                        } catch (IntentSender.SendIntentException e) {
                            // Ignore the error.
                        }
                        break;
                    case LocationSettingsStatusCodes.SETTINGS_CHANGE_UNAVAILABLE:
                        // Location settings are not satisfied. However, we have no way to fix the
                        // settings so we won't show the dialog.
                        break;
                }
            }
        });
    }

    public boolean handleOnActivityResult(int requestCode, int resultCode, Intent data) {
        if (requestCode == REQUEST_CODE_LOCATION_SETTING && resultCode == Activity.RESULT_OK) {
            if (isContinuousRequest) {
                requestContinuousLocation();
            } else {
                requestSingleLocation();
            }
            return true;
        }
        return false;
    }

    public interface LocationUpdateListener {
        void onLocationUpdate(Location location);
    }
}